Comparative analysis of the complete sequence of the plastid genome of Parthenium argentatum and identification of DNA barcodes to differentiate Parthenium species and lines

Shashi Kumar,Katrina Cornish,Colleen M Mcmahan,Frederick M Hahn,Maureen C Whalen

doi:10.1186/1471-2229-9-131

Shashi Kumar, Katrina Cornish + Show 3 more

Open Access

https://doi.org/10.1186/1471-2229-9-131

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Abstract

BackgroundParthenium argentatum (guayule) is an industrial crop that produces latex, which was recently commercialized as a source of latex rubber safe for people with Type I latex allergy. The complete plastid genome of P. argentatum was sequenced. The sequence provides important information useful for genetic engineering strategies. Comparison to the sequences of plastid genomes from three other members of the Asteraceae, Lactuca sativa, Guitozia abyssinica and Helianthus annuus revealed details of the evolution of the four genomes. Chloroplast-specific DNA barcodes were developed for identification of Parthenium species and lines.ResultsThe complete plastid genome of P. argentatum is 152,803 bp. Based on the overall comparison of individual protein coding genes with those in L. sativa, G. abyssinica and H. annuus, we demonstrate that the P. argentatum chloroplast genome sequence is most closely related to that of H. annuus. Similar to chloroplast genomes in G. abyssinica, L. sativa and H. annuus, the plastid genome of P. argentatum has a large 23 kb inversion with a smaller 3.4 kb inversion, within the large inversion. Using the matK and psbA-trnH spacer chloroplast DNA barcodes, three of the four Parthenium species tested, P. tomentosum, P. hysterophorus and P. schottii, can be differentiated from P. argentatum. In addition, we identified lines within P. argentatum.ConclusionThe genome sequence of the P. argentatum chloroplast will enrich the sequence resources of plastid genomes in commercial crops. The availability of the complete plastid genome sequence may facilitate transformation efficiency by using the precise sequence of endogenous flanking sequences and regulatory elements in chloroplast transformation vectors. The DNA barcoding study forms the foundation for genetic identification of commercially significant lines of P. argentatum that are important for producing latex.

Highlights

Parthenium argentatum is an industrial crop that produces latex, which was recently commercialized as a source of latex rubber safe for people with Type I latex allergy
Genome size and gene content, order and organization The complete nucleotide sequence of the chloroplast genome of Parthenium argentatum is represented in a circular map (Figure 1; Genbank Accession GU120098)
The inverted repeats (IR) are separated by small single copy (SSC) and large single copy (LSC) regions of 19,390 bp and 84,565 bp, respectively

Summary

Introduction

Parthenium argentatum (guayule) is an industrial crop that produces latex, which was recently commercialized as a source of latex rubber safe for people with Type I latex allergy. The complete plastid genome of P. argentatum was sequenced. Parthenium argentatum Gray, commonly known as guayule, is a shrub in the Asteraceae that is native to the southwestern United States and northern Mexico. Parthenium argentatum produces high quality rubber in bark tissue, which is under development for biomedical uses. The U.S Food and Drug Administration recently approved the first medical device made from P. argentatum natural rubber. Products made from P. argentatum latex are designed for people who have Type I latex allergies, induced by natural rubber proteins from Hevea brasiliensis. As an industrial crop that grows in temperate climates, P. argentatum represents a viable alternative source of high quality natural rubber

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